Lube oil containing oligomeric phosphorodiamidate

ABSTRACT

The manufacture of oligomeric phosphorodiamidate characterized by the formula:   WHERE R is alkaryl of from 12 to 24 carbons, R&#39;&#39; is lower alkyl of from 2 to 6 carbons and n is an average integer of from 1 to 4 and sulfurized derivatives thereof comprising contacting a primary amine of the formula:

United States Patent 119:

Haugen [4 1 Sept. 16, 1975 LUBE ()lL CONTAINING OLIGONIERIC PHOSPHORODIAMIDATE Related US. Application Data [62] Division of Ser. No. 210,238, Dec. 20, 1971, Pat. No.

Haakon Haugen, Beacon, N.Y.

[52] US. Cl. 252/493; 252/467; 252/389 A; 252/400; 252/959; 260/125 [51] Int. Cl. C10M H10 [58] Field of Search 252/499 [56] References Cited UNITED STATES PATENTS 2,146,543 2/1939 James et al. 252/499 2,l46,584 2/l939 Lipkin 252/499 2,151,380 3/1939 Flint et a]. 252/499 X 3,309, 17 3/1967 Wittncr et al 252/499 3,607,758 9/l97l Langenfcld 252/499 X 3,778,376 12/1973 Herber 252/499 X FOREIGN PATENTS OR APPLICATIONS 1,021,526 12/1957 Germany Primary Examiner-Helen M. S. Sneed Attorney, Agent, or FirmT. H. Whaley; C. G. Ries; Robert A. Kulason 57 ABSTRACT The manufacture of oligomeric phosphorodiamidate characterized by the formula:

where R is alkaryl of from 12 to 24 carbons, R' is lower alkyl of from 2 to 6 carbons and n is an average integer of from 1 to 4 and sulfurized derivatives thereof comprising contacting a primary amine of the formula:

where R is as heretofore defined with an alkyldihalo phosphate characterized by the formula:

where R is as heretofore defined and X is a halogen selected from chlorine or bromine utilizing a mole ratio of amine to said phosphate of between about l.7:l and 23:1 in the absence of solvent and catalyst at a temperature between about 170 and 200C. while continuously blowing the reaction mixture with an inert gas, recovering the oligomeric phosphorodiamidate product and optionally contacting said product with phosphorus pentasulfide utilizing a mole ratio of pentasulfide to product of between about 0.05:1 and 0.511 at a temperature between about 80 and 150C. in the presence of an inert solvent while continuously blowing the reaction mixture with an inert gas and recovering the sulfurized phosphorodiamidate reaction product. Both the phosphorodiamidate product and sulfurized phosphorodiamidate reaction product when incorporated in a hydrocarbon lubricating oil in an amount of between about 1.0 and 10 wt. percent function as a combination corrosion, oxidation and wear inhibitor (load carrying and extreme pressure additive).

2 Claims, No Drawings LUBE OIL CONTAINING ()LIGOIVHZRIC PHOSPHORODIAMIDATE This is a division, of application Ser. No. 210,238, filed Dec. 20, 1917] now U.S. Pat. No. 3,8l0,838.

BACKGROUN D OF INVENTION In the art of automotive lubrication there is a continuing search for additives which combine several functions such as oxidation inhibiting, corrosion inhibiting and load carrying (wear improving) abilities. One of the standard lube additives having this combined function of oxidation and corrosion inhibiting coupled with antiwear properties is zinc dialkyldithiophosphate. Although this material is very satisfactory, it does have the drawback of producing an ash when in contact with the high temperature areas of automotive engines such as in the exhaust valve region. Lubricant ash has been found to cause surface ignition in some gasoline en gines, and to cause fire-ring sticking in diesel engines.

In order to obviate the ash forming problem, numerous ashless additives for lubricating oils have been developed. One such ashless additive is tri(t-dodecylphenyl)phosphoric triamide. Although this material functions as an oxidation and corrosion inhibitor in lubricating oils, it does not impart good load carrying characteristics in said oil. Another prior developed additive is the 0,0-dialkyl phosphoroamidate derived from long chain primary aliphatic amines, e.g., 0,0- dibutyl phosphoroamidate derived from a mixture of t-C -C alkyl primary amines. Although this latter amidate imparted good load carrying properties to lubricating oils, it has no significant antioxidant effect. Thus, in order to impart both good oxidation and corrosion inhibiting effect and superior load carrying properties to a lubricating oil composition, it was necessary to employ both of the aforementioned ashless additives, whereas only a single additive was required in the case of the ash forming Zinc dialkyldithiophosphate for the aforementioned properties The use of multiple additives as opposed to a single additive to obtain a desired composite effect has economic disadvantages since it is normally more costly and requires a more complex blending procedure for the final lube composition.

Another prior problem in the art was in the preparation of the phosphoroamidate ashless additive, basic catalysts (e.g. alkyl amine) and solvent were required for satisfactory yields. The use of catalyst and solvent adds to process expense in terms of catalyst and solvent cost, added equipment and time for catalyst and solvent separation from the final product. Another preparation problem was phosphoroamidate amine hydrochloric salts were formed as byproducts. To remove these by-product salts from the amidate or reduce them to an acceptable level requires extensive water washing and filtration. Water washing step in addition to solvent and catalyst cost substantially adds to process cost and complexity and is very time-consuming because of the formation of stable emulsions during said step.

SUMMARY OF INVENTION I have discovered and this constitutes my invention a novel method of producing oligomeric phosphorodiamidic compounds and sulfurized derivatives thereof which when incorporated in hydrocarbon lubricating oils in an amount of between about 1.0 and l wt. percent form a resulting composition of improved oxidation and corrosion resistance and of improved load carrying ability. More specifically, the invention relates to a solvent free, non-catalytic method of preparing the novel oligomeric phosphorodiamidates and sulfurized phosphorodiamidate derivatives in which a hydrochloric acid salt by-product is not formed, thereby resulting in improved economics and method simplicity.

DETAILED DESCRIPTION OF THE INVENTION More specifically, my invention relates to the prepa ration of novel oligomeric Oalkyl-N,N'-bis(alkaryl) phosphorodiamidate which may be characterized for the sake of illustration by the formula:

where R is alkaryl of from 12 to 24 carbons, R is lower alkyl of from 2 to 6 carbons and n is an average integer of from l to 4, inclusively having a phosphorus content between about 2 and 10 wt. percent. The integer n" is determined to be average since the oligomeric product is in essence a mixture of diamidates of varying chain lengths. The sulfurized phosphorodiamidates contemplated herein are the reaction products of the aforedescribed phosphorodiamidates and phosphorus pentasulfide having a sulfur content between about 2 and 8 wtv percent and a phosphorus content between about 4 and if: wt. percent.

The complexity of the reaction products require their description in terms of process since they are in essence a mixture of compounds containing monoand polyalkyl-N,N'-bis(alkaryl)phosphorodiamidate groups wherein the exact nature of the intermolecular bonds have yet to be ascertained.

The aforedescribed oligomeric phosphorodiamidates are produced by contacting in the absence of a catalyst and solvent an alkarylamine of the formula:

where R is as heretofore defined with an O- alkyldihalophosphatc of the formula:

where R is as heretofore defined and X is chlorine or bromine. The reaction is conducted at a temperature between about l and 200C. utilizing a mole ratio of amine to dihalophosphate of between about 1.7:l and 2.3: l. During the reaction, the reaction mixture is continuously purged with an inert gas such as nitrogen to remove HCl by-product. Typical inert gas rates are between about 04 and 2 mls./min./gram. The reaction period is normally between about 10 and 30 hours, The crude product can be purified by standard techniques. e.g., extraction with an alkane such as normal pentane.

In the foregoing procedure, the defined combination of ingredients, quantities, conditions, the absence of liquid solvent and catalyst, and the employment of the reactant mole ratios are required to produce the oligomeric product and to prevent the formation of the undesired amine hydrochloride by-product salt.

In the preparation of the sulfurized derivative embodiment of the phosphorodiamidate described above, the oligomeric phosphorodiamidate product is reacted with phosphorus pentasulfide (P 8 at a temperature between about 80 and 150C. utilizing a mole ratio of P 8 to phosphorodiamidate of between about 0.05:1 and 0.5: 1 normally for a period of between about 1 and 6 hours. Under preferred conditions, inert liquid solvent diluent is employed such as liquid aromatic hydro- :arbons having a boiling point between about 80 and 130C, e.g., toluene and benzene. When inert solvent diluent is employed, it normally constitutes between about 20 and 40 wt. percent of the reaction mixture. Pressure is employed as necessary to prevent premature volatilization of solvent. At the end of the reaction, the sulfurized product is purified by standard techniques such as filtering the reaction mixture to remove excess P 8 and then stripping out the solvent under vacuum to form the sulfurized O-alkyl-N,N'-bis(alkaryl)phosphorodiamidate product having a sulfur content of between about 2 and 8 wt. percent and a phosphorus content of between about 4 and 16 wt. percent.

Because of the high viscosity of the non sulfurized and sulfurized products, they are preferably diluted, normally on a 5050 weight basis, with a hydrocarbon mineral oil, e.g,, a naphthenic oil of an SUS viscosity of about 100 at 100F. to form a lube oil concentrate for better handling.

Examples of the amine reactants contemplated herein are alkylated anilines where the total carbons of alkyl groups in from 6 to 18 such as p-hexylaniline, pnonylaniline, o,p-dibutylaniline, p-terL-dodecylaniline, and o-octadecylaniline.

Examples of the alkyldihalophosphate reactant contemplated herein are n-butyldichlorophosphate, n-butyldibromophosphate, ethyldichlorophosphate, ethyldibromophosphate, i-propyldichlorophosphate, n-propyldichlorophosphate, amyldichlorophosphate and hexyldichlorophosphate.

Examples of the oligomeric phosphorodiamidates and sulfurized phosphorodiamidates contemplated herein are O-n butyl'hLN'-bis-tert.-dodeeylphenylphosphorodiamidate mixtures, sulfurized O-n-hexyl- N,N'-bis(tert,-dodecylphenyl)phosphorodiamidate mixtures, O-ethy1 N,N-bis( p-tert-dodecylphenyhphosphorodiamidate mixtures, sulfurized O-isobutyl- N,N-bis(o,p-dibutylphenyl)phosphorodiamidate mixtures and O-n-pentyl-N,N'-bis(p-octadecylphenyl)- phosphorodiamidate mixtures.

The oligomeric phosphorodiamidates and sulfurized phosphorodiamidates of the invention when employed in the lubricant hydrocarbon mineral oil compositions contemplated herein are normally utilized in amounts of between about l and wt. percent, preferably between about 1 and 4 wt. percent, with the lubricating oil base constituting the major component of the composition, e.g., between about 8599 wt. percent. Among the suitable hydrocarbon mineral oil base materials are paraffin base, naphthene base or mixed paraffin and naphthene base distillate or residual oils. Paraffin base distillate lubricating oil fractions are used in the formulation of premium grade motor oils. The lu bricating base oil generally has been subjected to solvent refining to improve its lubricity and viscosity temperature relationship as well as solvent dewaxing to remove waxy components and improve pour of the oil. Broadly speaking, mineral lubricating oils having an SUS viscosity at 100F. between about 50 and 1000 may be used in the formulation of the improved lubricants of this invention, but usually the viscosity ranges fall between and 300 at F.

The novel mineral lubricating oil compositions containing the oligomeric phosphorodiamidates and sulfurized oligomeric phosphorodiamidates can contain other additives designed to impart other desirable properties thereto and/or to supplement the oxidation and corrosion inhibiting and load improving effect of the diamidate. Example supplementary additives include V1 improvers such as polymethacrylates; detergent dispersants such as alkaline earth metal alkylphenolate, overbased carbonated alkaline earth metal alkaryl sulfonates and ethoxylated inorganic phosphorus acid free, steam hydrolyzed, P s -polybutene (e.g., l 100 m.w.) reaction product detergent dispersant; and antifoamants such as polymeric siloxanes. In addition, supplementary oxidation and corrosion inhibitors and load improving agents such as a divalent metal alkyl dithiophosphate resulting from the neutralization of a P S -alcoho1 reaction product with a divalent metal or divalent metal oxide may be employed. Specific examples are the barium and zinc salts of a mixed alcohol (methyl-isobutylcarbonol and isopropanol)-P S,, reaction product. The metal dialkyldithiophosphates when used as a supplement are usually present in the lubricam in concentrations of between about 0.05 and 1.5

wt. percent.

The following examples further illustrate the products. method of preparation and compositions of the invention but are not to be construed as limitations thereof.

EXAMPLE I This example illustrates the preparation of the oligomeric phosphorodiamidate product,

In a 500 ml. flask there were mixed 208 grams (0.8 mole) of p-tert.-dodecylaniline with 76.4 grams (0.4 mole) of n-butyldiehlorophosphate. The flask was purged with nitrogen and heated gradually to C. and the temperature was maintained with nitrogen purging (200 mls./hour) for 16 hours and finally the reaction mixture was heated to C. for an additional 4 hours with continued nitrogen purging. The product was then kept at 125C. under reduced pressure (5 mm Hg.) for 1 hour and 242 grams (92% of theory) product was isolated. The resultant product was analyzed and found to contain: percent nitrogen 4.3, percent phosphorus 4.9, percent chlorine 0.4, total acid number (TAN) of 30. Further, analysis found the molecular weight to be 1880. The analysis indicated the product to be oligomeric O-n-butyl-N,N'bis(p-tert.dodecylphenyl)phosphorodiamidate apparently containing an average of about 3 phosphorodiamidic units.

EXAMPLE ll "lhis example illustrates the preparation of the sulfurized oligomeric phosphorodiamidate product.

To a 500 mls. flask 300 grams (equiv. 0.8 mole) of oligomeric phosphoroamidate produced in Example I, diluted on a 1:1 weight basis in naphthenic mineral oil having an SUS viscosity of about 100 at 100F. were mixed with 5.5 grams (equiv. 0.25 mole) P 8 in 150 mls. of toluene. The mixture was purged with nitrogen and heated to reflux l C.) for 4 hours, filtered and solvent stripped under reduced pressure. Analysis of the sulfurized O-n-butyl-N,N'-bis(p-tert.-dodecylphenyl)phosphorodiamidate found the following: wt. percent P 3.2. wt. percent S 1.1. wt. percent N 2.2. TAN of 40.

EXAMPLE 111 This example further illustrates the preparation of the oligomeric phosphorodiamidate product.

The procedure employed calls for mixing p-tert.- dodecylaniline with n-butyldichlorophosphate in a 500 mls. flask in the absence of base and solvent and heating and maintaining the reaction mixture in a temperature range of 170 to 200C. for a period of 18 to 30 hours under a continuous nitrogen purging. The product was then purified by reducing pressure to 5 mm Hg. at 125C. for a period of 12 hours. The product in all cases was determined to be essentially trirneric O-nbutyl-N.N -bis( t-dodecylphenyl )phosphorodiamidate.

The test data and results for five runs are reported below in Tables 1 and 1A:

TABLE I Rcactants Quantities and Conditions n-Butyl Ldodccyldichloro- React. React. aniline. phosphate. Temp. Time. Run No. mole mole C. Hrs.

TABLE IA Product Data Theory Yield, Yield. Analysis. wt. 9%" Run No. g.* Wt. fr P Cl TAN A 2 l 1 H5 2.6 2.3 .27 42 13 3M 75 2.2 2.3 .30 24 C 380 74 2.9 2.5 .33 26 D 1350 30 2.7 2.3 .72 38 E 1410 91 2.7 2.5 .23

Weight of a 1.1 weight ratio of tliamidate and naphthene lube oil of 100 SUS viscosity at 100"!- "Ba ctl on the 1 1 oil solution.

EXAMPLE IV This example further illustrates the preparation of the sulfurized phosphorodiamidate derivatives.

The procedure employed calls for the mixing of the oligomeric O-nbutyl-N,N'-bis( tcrt.-dodecylphenyl phosphorodiamidate prepared in Example 111. Run D with phosphorus pentasulfidc in the presence of toluene of a period of 5 hours under reflux conditions 1 15C.] while continuously purging with nitrogen and filtering the resultant material followed by stripping off toluene at up to 100C. under 5 mm Hg. The test data and results for six runs are reported below in Tables 11 and 11A:

TABLE 11 Rcactant, Quantities and Conditions Mole Ratio React. React. P 8, Amidate. Toluene Temp, Time. Run No. Amidatc Mole Mls. C. hrs.

F 0.2:1 0.1 100 110 3 G 0.2:1 0.1 100 110 3 H 0.2:] 0.l 100 110 3 1 0.2:1 0.5 100 115 h J 0.211 0.5 300 112 6 K 0111 0.5 300 112 3 TABLE [1A Product Data *Yield 50% Yield,% Analysis. wt. Run No. Active Theory P N TAN F 1 14 89 3.8 2.2 2.3 42 G 116 3.8 2.5 2.1 36 H 110 87 3.9 2.4 1.8 35 l (110 3.6 2.3 2.2 59 J 610 95 3.7 2.4 2.2 56 K 610 95 3.4 2.5 1.4 $6

Diluted in naphthenc lube oil o1 1005115 viscosity at F. on a 1:1 weight ratio basis.

"Based on the l'l oiLdiamidate mixture.

EXAMPLE V This example illustrates the oxidation and corrosion inhibiting effect and load improving ability of the oligomeric phosphorodiamidate and sulfurized phosphorodiamidate products of the invention as well as illustrating the lubricant compositions of the invention.

The tests employed are as follows:

A. 4-Ball Wear Test described in US. Pat. No. 3,050,466 measures load carrying ability of the test oil in terms of scar diameter on a steel ball with increasing scar diameter denoting decreasing load carrying ability.

B. The MacCoull Corrosion Test described in US. Pat. No. 2,709,682 measures oxidation and corrosion inhibiting ability of the test oil, the corrosion being measured in terms of bearing weight loss and Neut. No., the greater the bearing weight loss and Neut. No. increase, the greater the corrosion; the greater the viscosity increase the greater the degreee of oxidation.

C. Copper Strip Corrosion Test (ASTM D-l30-68) which consists of placing a copper strip in the test composition for a period of 3 hours at 212F. and then giv ing the strip a rating of from 1 to 5, 1 representing none to slight tarnish and 5 representing heavy corrosion. Further. a rating of 18 represents a greater degree of tarnish than a 1A rating.

D. Oxidation Absorption Test described in The Review of Scientific Instruments". Vol. 42. No. 4. pgs. 471-474. April 1971 consists of passing oxygen into the test composition maintained at a temperature of 340F. and measuring the period of time which it takes to absorb 500 mls. of oxygen. The longer the time to absorb the 500 mls. of oxygen. the greater resistance to oxidation.

The materials employed in the above tests and their shorthand designation are as follows:

1. OP: 1:1 wt. ratio composition of naphthcnic lube oil 100 SUS at 100F.) and trimeric O-n-butyl N,N'-bis( t-dodecylphenyl )phosphorodiamidates. the composition having a P content of 2.9 wt. percent and an N content of 2.5 wt. percent and pre pared in Example "I, Run C.

2. SOP: 1:] wt. ratio composition of naphthenic lube oil (-l SUS at 100F.) and P 5 sulfurized tri- In the foregoing table the reason compositions based on Oil B are poorer than compositions based on oil A in the oxidation area is because of the pro-oxidant effect of the overbased calcium sulfonate ingredient meric O-n-butyl-N,N' bis(t-dodecylphenyl)phos- 5 therein phorodiamidate, the composition having a wt. per- 1 claim: Cent P of f N of and WL percent 1. A hydrocarbon lubricating oil composition com- S of prepared ExamplC Run prising a major amount of hydrocarbon lubricating oil 3. Zn. Salt: Zinc salt of mixed alcohol (methylisobuand between about 01 and wt percum Ufa product tyl-carbiriol and isopropanol )-P S in mineral lubri- 10 Of an oligomeric o alkyl N N, bis(alkaryl) p caung ml contfnmng abcfut Percent phorodiamidate having an average from 1 to 4 phosformed by lieactmg methyl lsobutylcarbmol and phorodiamidic groups and a phosphorus content of bepropanolwnh lazsfimarimo 9 27:23:] and tween about 2 and 10 wt. percent prepared by the fmjmmg Zmc l l method comprising contacting an amine of the formula 4. Base Oil A: Paraffinic lubricating oil of an SUS vis- RNH2 where R is alkaryl of from 2 to 24 carbons with cosity of about 340 at 100F. an 81k 1 ihalo hos hate of the formula: 5. Base Oil B: Parafi'inic lubricating oil of an SUS vrsy p p cosity of about 340 at 100F. containing calcium carbonate overbased calcium sulfonate and ethoxylated. inorganic phosphorus acid free, steam hy- 2 drolyzed polyisobutylene (i100 m.w.)-P S,, reaction product, said base oil having a 0.0375 wt. percent P and 0.35 wt. percent Ca content. The test data and results are reported below in Tables II and "IA: 25

TABLE III Compositions Additive Addmvc where R is alkyl of from 2 to 6 carbons and X is chlo- Nunc 0 A 0 rine or bromine utilizing a mole ratio of said amine to GP 1 2 said dihalophosphate of between about 1.7:l and 2.3: I Q, 322 H A Mi at a temperature between about 170 and 200Cv in the 0P 4 B absence of inert diluent solvent and in the absence of II SOP 4 B .it m 2 Sun U 8 (H0 5 catalyst while continuously blowing the react on mixi/lIl ()P 3 H 0,07 ture with an inert gas and recovering said oligomeric X :8?" 2- B 8 phosphorodiamidate.

Zn Sn 2. A hydrocarbon lubricating oil composition of 3 8- claim 1 where R is p-tert.-dodecylphenyl, R is n-butyl, X is chlorine and said phosphorodiamidate contains an ,DUMI mm Admiw average of about three phosphorodiamidic groups.

TABLE lllA Oxidation. Corrosion. Wear Data 4-Bzill" Wear MacCoull Cu Scar Diam. Vise. Strip Adsorp Run mm BWl. g. N.N. lncrfii Corr." Hrs.

I Hi} I72 12.8 400 IA 17 II 0.54 4 5 IA 4 III 037 h l 5 2B Iv 0.37 4 Li 5 IA 20 v 0.72 44 2,3 19 IB 2&- vi 0.44) 5 r5 l4 2( 25 WI (1.30 4 2+1 i2 1A in VI" n39 3 1.7 15 1B 21 IX (L35 3 2.2 20 ii; 21 x 0,36 m 9.: IA 4 XI LOU M0 451) IA 2 "2 hrs 40 k :oo'i (\Ull RPM UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE 0F CQECTIN PATENT NO. 1 3 905 0 DATED September 19, 1975 myemomo HAAKON HAUGEN Itis certified that error appears in the above-identified paientand that said Letters Patent are hereby corrected as shown below:

Column 3, line 35, insert -any after "are".

Column 3, line 36, change "in" to -is-.

Column 3, line 47, change "tert.dodeoylphenyl" to -(ptert.dodecylphenyl)--.

Column 8, Claim 1, following line 10 thereof, insert the formula:

Signed and fieaied this first Day of June 1976 [sen] Arrest:

liuTu eausou v I c. MARSHALL DANN Anesn'ng Officer Commissioner 0] Patents and Trademarks UNITED STATES PATENT AND TRADEMARK OFFICE EETEHCATE PATENT NO. 3,905, 908 DATED September 19, 1975 lN\/ ENTOR(S) HAAKON HAUGEN It is certified that error appears in the above-identified parent and that said Letters Patent are hereby corrected as shown below:

I! II Column 3, line 35, insert anyafter are Column 3, line 36, change "in" to is-.

Column 3, line 47, change "tert.dodecylphenyl" to -(p-tert.-dodecylphenyl)-.

Column 8, Claim 1, following line 10 thereof, insert the formula:

R'0P=O Signed and geaied this first Day of June1976 seem] AIM-U.

Rum c. MASON v I c. MARSHALL DANN Arresting Officer (ommr'm'uner uflarenrs and Trademarks UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,905,908 DATED September 19, 1975 INVENTOR(S) 1 HAAKON HAUGEN It is certified that error appears in the above-identified patent and that said Letiers Patent are hereby corrected as shown below:

Column 3, line 35, insert any after "are".

Column 3, line 36, change "in" to is.

Column 3, line 47, change "tert.-dodecylphenyl" to (ptert.clodecylphenyl).

Column 8 Claim 1, following line 10 thereof, insert the formula:

R'O-P=0 Signed and Scaled this first Day of June1976 [SEAL] Arrest:

Rum c. msou c. mnsmu DANN Alluring Officer Commissioner nj'lan'ms and Trademarks 

1. A HYDROCARBON LUBRICATING OIL COMPOSITION COMPRISING A MAJOR AMOUNT OF HYDROCARBON LUBRICATING OIL AND BETWEEN ABOUT 0.1 AND 10 WT. PERCENT OF A PRODUCT OF AN OLIGOMERIC O-ALKYL-N,N''-BIS(ALKARYL) PHOSPHORODIA MIDATE HAVING AN AVERAGE FROM 1 TO 4 PHOSPHORODIAMIDC GROUPS AND A PHOSPHORUS CONTENT OF BETWEEN ABOUT 2 AND 10 WT. PERCENT PREPARED BY THE METHOD COMPRISING CONTACTING AN AMINE OF THE FORMULA RNH2 WHERE R IS ALKARYL OF FROM 12 TO 24 CARBONS WITH AN ALKYL DIHALOPHOSPHATE OF THE FORMULA:
 2. A hydrocarbon lubricating oil composition of claim 1 where R is p-tert.-dodecylphenyl, R'' is n-butyl, X is chlorine and said phosphorodiamidate contains an average of about three phosphorodiamidic groups. 